$%^&ing emissions!!

[beandip]

Ztherapy will recommend SM needles. They will never pass emissions . Install a set of 54 needles and the engine will run great . The only criticle setting on the float is to not make the fuel level too high . There are only nozzles available for the '70Z , at least from Nisson. The nozzle is a 5 min job to change , the needle another 5min for each carb . At idle when I shut the engine down and remove the float chamber cover , I have about 1/2 inch of gas in the bowl . I have never had a problem with the engine running lean. Are these carbs 3 screw or 4 screw units ? 3 screw SUs , and a matching intake have water flowing through the carb . You must first drain the coolent level down past the level of the carb. That is if you remove the carb to do this . I have a '82ZX in my 240Z with SUs and I am running these needles . All the best , Gary

[ddezso]

Deleting duplicate post.....

[ddezso]

I believe I have the 4 screw variety. Here's a pic.

Would fresh needles and nozzles remedy this situation where the screw to lean the mix is bottomed out? I am trusting this mechanic and he has done this forever but I hate not understanding it myself....

How much are needles and nozzles from Nissan? Less than the 150 for all the ZTherapy stuff in the kit?

[kenz240z]

Here are some ideas I came across on another site for passing an emissions test. Some may not even be applicable for a Z car. I haven't had to use any of these methods, so I can't vouch for them...try at your own risk!

>FWIW, a very interesting collection of ideas gathered from various sources and from people that had emissions challenged vehicles but found ways to pass the test ...

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emissions components which may be inspected by officials for proper operation:

EGR Valve, Air Pump, Charcoal Canister, EVAP System, Smog Pump, Oxygen Sensor, Intake Manifold, Exhaust Manifold, Fuel Pump, Turbo, Supercharger, Header, Camshaft, Fuel Filter, Air Filer, Oil Filter, Carburetor, Fuel Injector, Preheat Tube, Air Injection, Check Valve, Muffler, Solenoid, Fuel Mixture Solenoid, Catalytic Converter, CAT, Heat Riser, OBD II System, On Board Diagnostics Computer and Vacuum Lines.

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GUMOUT, emissions Reducer, 12 oz bottle

"at the pump pour the bottle then fill tank .. in this initial tank, emissions may increase as Gumout works to remove deposits and expel via the exhaust .. run until tank is near empty .. refill tank .. do not perform emissions test until 2nd or third tank where the emissions benefits will show ....."

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make sure your gas tank is only 1/4 to 1/2 full and put 1/2 the bottle of methyl hydrate (fondue fuel) in the tank

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Pour pure (90%+) isopropyl alcohol into your fuel tank, it will help to clean up your exhaust emmissions and get your car through the smog tests that most states currently use. Use two 16oz bottles for ten gallons of premium fuel.

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pour two litres of methyl hydrate into 1/2 tank of fuel

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pour two quarts of pure denatured alcohol into 1/4 tank of fuel

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disconnect the harness from one injector. The engine will only run on 7 cylinders, but it will pump one cylinder worth of air into the exhaust on every cycle, which serves to dilute the mixture from the other cylinders.

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Change oil and leave it a quart low. New oil seals better and low level minimizes the chance of splash onto the cylinder walls. Burnt oil is another source of HC.

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clean the engine. Burnt oil is another source of HC.

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Change the engine oil just before you go to test. Fresh 20/50 seals better than any oil with 50 or more miles on it. The idea is to reduce hydrocarbons (HC),

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leave the tank half full or less. The evap system can be overloaded with a full tank, increasing HC.

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Bring it in real hot from a highway run. The O2 and cat work best when hot and the throttle body is heated by engine coolant, pre-heating intake air.

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Drive it on the freeway for about 10 miles before you go to the test in order to be sure that the engine is at full operating temperature

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put in the highest octane gas you can find, change the oil, and retard the timing slightly (3 deg).

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Just before the smog test fill up with good winter "Arizona" gas. i.e. unoxgenated gas with enough volatility to easily ignite. ("Winter Gas" is more volatile then "Summer Gas".)

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Retard the ignition timing about 3 degrees to help reduce the NOX emissions.

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take out air filter

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Use a low-restriction air cleaner set. Hellings has one about 1/2" thick with metal wire for a filtering medium. It will only filter out large rocks, but it flows very freely.

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Run the fuel tank down as far as possible and refill it just before the test. Fuel has a ‘half-life' and it does not burn as well if it has been in the tank for 90 days or more

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Put in a new set of spark plugs, gapped.

Convert from carbon core ignition wires to the solid core (metal) type.

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Capped off PCV connection to manifold

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make sure the tires are inflated to MAX for the dyno test.

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fuel cap sealing correctly

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blowby/crankcase fumes being re-ingested through the air cleaner and throwing the tailpipe readings way off. reroute the crankcase fumes out of the compartment via a "road draft tube"

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[montoya_fan01]

HeHe, I got dinged for the Mitsu's fuel cap not sealing correctly also. I had no idea they would check something like that.

[Arne]

Would fresh needles and nozzles remedy this situation where the screw to lean the mix is bottomed out? I am trusting this mechanic and he has done this forever but I hate not understanding it myself....

In my opinion - no. It's possible, but I don't think it likely that the nozzles and needles are your problem. If the mixture is too rich with the adjuster screws all the way up, there is probably something else wrong. The main causes could be:

1. The float level is too high
   
2. The nozzles are sticking (i.e. - as if the choke was stuck on)
   
3. The nozzles are badly worn (needle orofices)
   
4. The needles are badly worn
   
5. The needles are wrong
   
6. The needles are very badly adjusted (mounted way too far up in the piston, not a likely situation)
   

Note that the fresh needles and nozzles only address numbers 3, 4 and 5. Number 1 will cause the same problem with new parts.

I agree with Gary that considering your issue, you probably don't want SM needles, or even the early stock N27 needles used in the earliest cars, as those are the richest choices. N54s are probably your best choice for this, assuming you do get new ones.

But I still strongly doubt that the needles and nozzles are the problem. In this situation the float level MUST be your first check. If it's too high, nothing else you do will help at all!

[kenz240z]

A coupleof years ago I bought a '75 Chevy convertible from a guy out in a small town in northeast Colorado. I brought it back to Longmont (about 25 miles north of Denver) and took it in for emissions testing. As far as HC%, CO%, CO2%, etc... everything passed. But, the tester failed it because:

A. There wasn't a catalytic converter

B. The fuel filler restrictor was oversized

Never mind that the car passed the actual emissions test! Out in NE Colorado emissions tests aren't required, and the PO had a dual exhaust system put on the car. The original cat was removed, and none were installed on the new exhaust.

As for the fuel restrictor, I can only speculate that it became enlarged by 30 years of jockeying the nozzle at the tank. It seems like most of the nozzles on the fuel pumps here have big, bulky attachments with little advertisements in them. The purpose of the fuel filler restrictor is to prevent putting leaded gas in the tank, as the nozzles apparently have a different diameter. Not sure where I could even get leaded gas around here...

So, I had a muffler shop remove the dual exhaust, put in a y-pipe and a cat and a single exhaust. I was able to bend part of the fuel filler restrictor to reduce the diameter. I took the car back in, and it had to undergo the full test again. At least it passed the second time!

When I bought my Z I took it to a Z mechanic nearby to prepare it for the emissions test. I then took it in for the test and it failed the CO%. So, I took it back to my mechanic. He ended up taking the car to a different testing facility and got it to pass.

[ddezso]

I read through all of the state laws for Arizona last night and I have concluded that I dont need an emissions test. The official law disagrees with the state website and brochures. Here is who the website and brochures exempt:

Exempted Vehicles

Model year 2001 or newer, except reconstructed, vehicles

Model year 2003 or newer original equipment alternative fuel vehicles

Model year 1966 and older vehicles

Apportioned vehicles (licensed in more than one state)

Electric powered, golf carts or vehicles with engine displacement of less than 90cc

Vehicles leased to a person residing outside the emission control areas

Vehicles transferred between dealers (wholesale)

If you go to the state law, collector vehicles are also exempted. What defines a collector vehicle? Here is what the law says:

Z. For the purposes of this section, "collectible vehicle" means a vehicle that complies with both of the following:

1. Either:

(a) Bears a model year date of original manufacture that is at least fifteen years old.

( Is of unique or rare design, of limited production and an object of curiosity.

2. Meets both of the following criteria:

(a) Is maintained primarily for use in car club activities, exhibitions, parades or other functions of public interest or for a private collection and is used only infrequently for other purposes.

( Has a collectible vehicle or classic automobile insurance coverage that restricts the collectible vehicle mileage or use, or both, and requires the owner to have another vehicle for personal use.

So now I get to print out the law and go to the DMV and argue with them that their policies are inconsistent with the law.

That doesnt mean I dont want to fix my rich mix but I gotta get this thing registered.

The moral of the story?

From what you all have said, and what I have experienced, the state employees don't know what they are talking about....

[montoya_fan01]

so which of those requirements does your car fit into?

please keep us posted with your progress on this issue.

[ddezso]

You have to meet 1 of the 2 things in section 1 and it is certainly more than 15 years old. I feel I meet both of the second requirement because I only drive it once a week to go to the car show, or maybe to dinner with my wife. I have collector car insurance which limits the mileage. . .

I'll be sure to tell you how my battle with the state turns out. It pays to read the laws rather than trust the folks at the DMV. They are all really nice but I doubt they have read the laws.

[ddezso]

I guess the law I was referencing hasnt passed yet so that didnt work. I went back to the emissions waiver station with an estimate from my mechanic to fix the carbs and after 6 guys poked at the car for 30 minutes they gave me a waiver.

I am proud to say I finally have a legal and legit car and can drive without the law getting me. Now I have 1 year to get it fixed to pass emissions, or wait for the new law to be enacted.